1. Field of the Invention
The present invention relates to breast pumps designed for extracting breast milk from a mother into a container for storage and infant feeding purposes.
2. Related Art
Working mothers often use breast pumps to extract milk from their breasts into a bottle for later feeding of their infant while the mother is at work or separated from the infant for some other reason. Current breast pump designs include a suction cup or breast shield for engagement over the breast and a pumping device connected to the breast shield, with a connector for attaching a container to the breast pump outlet to receive the milk. Manual breast pumps of various designs have existed for many years. These designs are not particularly efficient since they require use of small muscle groups of the arms and hands, and mothers using manual pumps of these designs generally tire easily, often before sufficient milk is collected. In general, the easier a pump is for the mother to operate, the more milk will be collected.
Some automated breast pumps have been devised in the past in which an electric motor or other power source drives a piston or diaphragm to operate the pump. U.S. Pat. No. 5,007,899 of Larsson, the contents of which are incorporated herein by reference, describes a drive unit adapted for use with a manual piston breast pump. The drive unit has an adaptor for releasably securing the cylinder of the breast pump to the unit, and a clamp on a drive arm of the unit is releasably secured to the breast pump piston. A motor in the unit drives the drive arm back and forth to reciprocate the piston at a desired suction stroke.